Desert Blooms

Southwest Yard & Garden Question: Our mesquite trees are experiencing what appears to be a girdler bug attack. This is the first time we have experienced this. How harmful are they, and what can be done to rid these pests? -         Jack D., Doña Ana County, NM Mesquite girdler. (photo credit: Dr. Salvador Vitanza, previously with TexasAgriLife, El Paso, TX)   Whiteish band on stem near middle of the photo was caused by the mequite girdler. (submitted photo) Mesquite stem die back caused by the mesquite girdler. (submitted photo) Girdling visible even though the stem is out of focus. (submitted photo) Answer: In order to answer your question, I enlisted the help of NMSU Extension Horticulture Specialist and NM State Entomologist, Dr. Carol Sutherland . Here is her response: Yep. The culprit here is a type of long-horned beetle known as the “mesquite girdler” ( Oncideres rhodosticta ). Adults are about a ...

Southwest Yard & Garden | Marisa Thompson, PhD Question: I have a spot with southern exposure in my yard where I would like to plant a quaking aspen (5,792 ft elevation).  Is quaking aspen suitable for this environment? -         John R., NE Albuquerque, NM Answer: I traveled all over New Mexico in the past few weeks, enjoying the striking fall colors. It is no surprise that you are feeling inspired to plant such a sensational tree. Spoiler alert: quaking aspen ( Populus tremuloides ) prefer the cooler climates offered above 7,500 ft. Some say they can be planted above 6,000 ft, but only with very special care and only in a very cool spot along the north or east side of a building where the soil remains mostly shaded. Even if you babied your tree by giving extra water, it would likely suffer from heat stress every summer. Retired NMSU Extension Horticulture Specialist, Dr. Curtis Smith, says he has seen just that in the NE heigh...

Southwest Yard & Garden | Marisa Thompson Question: Can you tell what seems to be plaguing the various rosebushes in my backyard?  -           L. Peters, Sandoval County, NM   Answer: Thanks for sending such great photos with your rosebush question. These photos depict rose foliage with varying degrees of browning edges on the leaflets and some white crusty buildup on leaflet surfaces, especially at the margins. Some of the leaflets have a burned look with black edges. First off, the leaf margin damage looked to me like salt burn, and I asked Dr. Curtis Smith, retired NMSU horticulture specialist, to weigh in. Dr. Smith agreed that the tissue necrosis at the leaflet tips and margins might be due to salt burn. Salt accumulation at these points is caused when dissolved salts are brought up to the leaves from the roots during transpiration. This could be due to salts in the soil, in the water, or just accumulated ...

Question: How much should I be watering my trees?  -    Multiple Gardeners from All Over NM Answer (Part 2): In last week’s column , we learned about how the type of soil in your garden affects tree water requirements. Now we will focus on other considerations, such as rates of water movement, tree species, age, canopy size, and seasonal fluctuations in water needs. Plants take water up from the soil through their roots all the way to the leaves where it is released into the air. Transpiration is the process by which a plant loses water, primarily through pores in the leaves called stomata. This is a necessary process that involves the use of about 90% of the water that enters the plant through the roots. The other 10% of the water is used in chemical reactions, like photosynthesis, and in plant tissues. Transpiration is necessary for mineral transport from the soil to the plant tissues, for the cooling of the plant through evaporation, for moving sugars and pla...

Question: How much water does my tree need?  - Multiple Gardeners from All Over NM Answer: I wish I had a simple answer. Since starting my position as NMSU’s extension horticulture specialist two months ago, I have heard this question in nearly every community I visited. Additionally, I have been pondering this question for years in my research as well as in my own garden. In order to address the complicated question, I split this column into two weeks. This week I describe how the type of soil around your tree plays a big role in determining water requirements. Here's a link for Part II: https://nmsudesertblooms.blogspot.com/2017/10/knowing-how-much-to-water.html . Even if you know the species of your tree and try to look up water requirements, you will likely find a complicated answer. For example, in Judith Phillips’ revised New Mexico Gardener’s Guide the watering directions for desert willow are as follows “Until it reaches the desired height, water to a depth of t...

Southwest Yard & Garden | September 30, 2017 Question: I have little time to tend to a garden. What types of fruits, vegetables, or spices do well with only a few hours of TLC a week?  L. Peerman, Las Cruces, NM Answer: Successful gardening will always rely on a certain level of dedication and attention to detail. Knowing what species do best in your area, when to plant, and basic maintenance are key parts of making any garden venture ‘easy’. That being said, peaches, arugula, kale, Chinese cabbage, oregano, and rosemary are among the first that pop into my mind as being remarkably easy and rewarding for us in Las Cruces. Partial harvest from two peach trees in Las Cruces But something tells me plenty of readers around the state are wanting an answer to your question too. I asked a few seasoned growers to weigh in on their most recommended plants for low input gardening. Some of their responses surprised me. Curtis Smith in Albuquerque said, “I like golden...

Southwest Yard & Garden | September 23, 2017 Question: What are the beautiful golden strands that show up from nowhere, and seem to attack the goatheads? Can they be moved from one patch to another where it is not growing yet? B. Stanley, Chaparral, NM Dodder strands on puncturevine (credit: Dr. Beck) Dodder forming mats on weedy roadside (credit: J. French, NMSU Extension Plant Pathology Specialist)   Answer: In order to fully address your question, I have consulted with NMSU Weed Specialist, Dr. Leslie Beck. Those golden strands are from a climbing parasitic plant commonly known as dodder of the genus Cuscuta .  It is a close relative of morningglory and the dreaded field bindweed, which are all in the plant family Convolvulaceae. You may have seen time-lapse video footage of vine tips making slow, circular, swaying motions as a way of searching for sturdy branch to climb. Dodder grows in a similar way. Dodder germinates from seed in the...